With consumer show CES set to have gadget nerds the world over fixated on Las Vegas next week, rumours of a new Apple television are flying thick and fast - once again.

We've had reports this week of a 50-inch TV apparently under wraps in Sir Jony Ive's famously super-secret lab in Cupertino and speculation has been rife since October about the integrated HDTV device with the 'simple user interface' that Steve Jobs seemingly told biographer Walter Isaacson.

Now Apple Insider has discovered a patent application made by Apple in September 2011 that shows the company has explored building displays with dynamic backlight adaptation for better picture quality.

A pertinent portion of the patent filing states: "Many video images are encoded with black bars, e.g., non-picture portions of the video images. These non-picture portions complicate the analysis of the brightness of the video images, and therefore can create problems when determining the trade-off between the brightness of the video signals and the intensity setting of the light source. Moreover, these non-picture portions can also produce visual artifacts[sic] which can degrade the overall user experience."

Sir Jonathan Ive in his sealed lab at Apple

Rumours abound of a 42 or 50-inch HDTV in development at Sir Jonathan Ive's Apple workshop

"Apple's solution is a complex processing system that could 'spatially vary visual information' on a display," said the site's Neil Hughes. "This would dynamically adjust the backlight source on a screen, like a high-definition television set, in a way that would improve the picture quality. The display would have multiple brightness settings for its backlight based on the processing of the image. For example, the "picture portion" of the screen would be illuminated by LED backlighting to an appropriate level, whereas the "non-picture portion," which would include the black bars, would have a different backlight."

Rumours of a TV from Apple have been circulating for years of course. As for the choice of timing, Apple has form when it comes to a headline-grabbing coup in early January. The company unveiled the iPhone at Macworld Expo in January 2007, in the process simultaneously stunning and snubbing the giants of the consumer technology world attending CES in the same week.